Lifting device.



J. MACDONALD. v UFTINGDEVICE. APPLICATION man MM l5. 191e.

Patented Apr. 24,1917.

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LIFTING DEVICE. APPLICATION FILED III/w15, I9I6.

Patented Apr. 24,1917.

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UNITED ermee-PATENT OFFICE.

JAMES MAoDoNALnoF CHICAGO, rIgLINoIs.

LIFTING DEVICE.

Appueation'lea May 15, 191e. serial No. 97,630.1

Be it known that I, JAMES MACDONALD, a citizenvof the United States,residing at Chicago, in the county of Cook and State of lllinois, haveinvented certain new and useful Improvements in Lifting Devices, ofwhich the following isadescription, referencebeing had to theaccompanying draw,- ings, forming a part of `this specilication, inwhich corresponding numerals of reference in the different figuresindicatelike parts.

The object of myiinvention generally Specification of Letters Patent.

stated, is to provide a simple, cheap 'and' ef.`

fective liftingk device adaptedr fory the lifting of heavy loads where"great power rather than speedis an essential; such, for example, asinthe raising of formsv used i'nzconcretey wall or other monolithic`construction where the use 'ofjack screws or similar appliances'` arerendered impractical except at vprohibitoryf expense. I accomplish saidobject' by means of primary and secondary frame elements, combined withindependent gripping members adapted tofgrip a vertical supportingmember suchas a rod or bar,jeither suspended from above or4 rigidly`"supported from beneath, in such ay way as to 'alternately,k gripandrelease .saidsupporting member so that "a reversal ,of the vlever bywhich they are actuated may'lserve to-lift the entire devicejstepi by.Vstep together with its yload,`,said device being; so'v combined andactuated with referenceto said vertical sup-l porting memberjas to actconcentrically thereon so as to avoidany lateral distortion thereof',thereby insuring Avthefupward movement of, both lifting deviceandyloadkin a vertical plane, all kof which ishereinafter more particularlydescribed and kdeinitely pointed outin' the claims. i

In the drawings Figure 1, is a side "elevation of my im-` provedliftingdevice together with a verwork bolted tok saidlifting device.

Fig. 2, is a rear view taken at right langles to that shown in F-i'g.`1..

Fig. 3, `is a Icentral.longitudinal sectionall tical supporting rod anda form for concrete` Patented 6, is a like view taken upon the line 6,Fig. 3, and i Fig. 7,' is a side elevation of the machine as it wouldappearwhen not in use.

Referring to the drawings, 1 indicates generally an upright support orframe formed fromcast metal having a body portion consisting of verticalsupporting memsecondary or auxiliary framepor'ti'on consisting' in theexample shown', of parallel plate-like members `7`, 7 which are yspacedapart and provided with enlarged concentric bores at their -upper endsintowhich trunnions 8, 8, extending laterally in opposite directionsfroma `bifurcated head 9, are journaled. In'` addition to saidvtrunnions 8 are' secondary trunnions or .bosses 10, 10,

which in the example shown are illustrated as partsv of a singlel shaftcut away at 11,'

Figs. 3 and 5, for the purpose hereinafter stated. Thesecondarytrunnions 10, are in eccentric relation to, the trunnions 8, as bestshown in Figs. 3V and 5, and they with the head form a pivotedconnection "between the primary andI secondary frames. The head 9 isprovided with a rear extension 12 having a socket 13 thereinv for `thekreception of` a leverarm 14. It'will be understood from what .has beenstated that the members 7 which I have' termed the secondary frame,

are suspended from the eccentric head9, so that vone lframe may belcaused to have ya slight. up and down movement with respect to theother when'the head is oscillated by the` movement of the lever-arm 14;.Dependv ing portions 15, 15, aty the lower ends ofthe view ofysaidliftingdevice as' it would ap.`

pear 'in operative connection withy a supportin`rod.' y l y ig. 4:, 1s asectlon in plan taken upon the line4,Fig.3. y

Fig. 5, 1s a sectioniin' plan taken upon the line5,`Fig.l3.j`' f y fparts 7 Figs.`2 and, are provided with vertical-notches 16 `for thereception of guidelugs` 17 rigidlyw attached to the web 4, to guide themembers 7 in their up and down movement. Counterpart cam members 18, 18,better shown in Figsj and 4:, are provided with trunnions 19, which arejournaled in a common horizontal plane in the mem- Apr. 24, 1917.

bers 7. Each of said cam-members is provided with an eccentric serratedgripping jaw or cam 20, the opposing serrated lfaces 2l of which arespaced apart or separated from each other a predetermined distance toprovide for the insertion between them of a rod or bar 22, which theylare adapted to grip in the manner and for the purpose hereinafterdescribed. Arms 28 are formed upon or rigidly attached to the members 18and extended in opposite directions;y therefrom as shown, said 'armsbeing preferably limited in `their upward movement by means of guards24:, attached in any approved way to the main frame.

A lever arm 25, is provided with trunnions 26, which are `pivoted linlugs 27, extending rearwardly from the parts 6. Said lever is providedupon its forward end with a serrated gripping jaw 28, adapted to gripthe rod or bar 22 when the free end of the lever is pressed downwardlyso kas to Asuspend the frame from said rod and prevent the downwardmovement of said frame. A bore 29, Fig. 3, is formed in the web 4, andserves as a guide 'to aid in holding said rod in concentric relation tothe frame.

The laterally extended base plates 3, are provided with bores 30, Fig.4, for the reception of bolts 31, Figs. l and 2, 'adapted to be extendeddownwardly through any 'suitable beams or other members 32, for thesuspension therefrom of the usual concrete form 33.

The operation of the device for lthepurpose speciiedis as follows: Inordinary concrete construction work 'the form 38, "of Ypredeterminedheight, preferably about three or four feet, is placed upon the groundin position to receive the concrete filling. In the example illustrateda `section 'of a straight wall is indicated but it is manifest that the'form may be varied to adapt itto the character of the structureinvolved, It is essential that the entire form or forms should be `solifted 'as to be lrept substantially level and in a vertical plane,thereby requiring approximate uniformity of laction throughout theentire length. In order to insure such action a considerable number oflifting machines may and usually would, be required, the number beingproportionate to the relative weight of the forms and the character andextent of the structure to 'be erected. A supporting rod 22, would,therefore, be required for each machine and these should be placedsufhciently near to` each other to enable the formto be lifted withoutdistortion. The machines being ypositio'iie'd and rigidly bolted to the'form vas described,

the rods 22, are projectedv downwardly' through the body ofthe deviceand form in the manner shown until their lower ends rest upon a solidfoundation. lSaidfrods are located in a vertical plane preferably midwaybetween the walls of the formas shown in Fig. 2. A lling of concrete 34,is then laced in the form and allowed to remain ong enough to insure aninitial set. When it is desired to lift the form, the lever 25 of thefirst machine in the series is depressed so that'the holding cam 28,shall be caused to have a firm grip upon the rod 22. The lever- 14 isthen raised to the position shown in Fig. 3, thereby lifting the parts 7and with them the pivoted members 18, and in turn causing the serratedcams 120, to slide upwardly upon and in contact with the rod 22,diametrically opposite to each other. When the lever 14 is raised to itsfull height the arms "23 are brought into contact with the guards '24with 'suiiicient force'to cause the cams 20 to `frrnly'grip the rod.'Thereupon the lever 14 is depressed, whereupon 'the trunnions 8, actingas a fulcrum for the lever, cause the trunnions 10 to "be lifted, thuscarrying with them the frame 1 and Wi'thit the form, which movement ispermitted 'by the gripping of the cams 20 upon the suspendingrod,thereby serving as a rigid support for the members 7, andthe'si'multaneous slipping uponsaid rod ofthe auxiliary holding cam 28.It will thus be seen that the frames are always caused to move 'inopposite directions with respect to each other by alternately climbingor asc-endingthe supporting rod step-by-step, one being stationary whilethe other is advanced.

VVhile-the' lifting device is intended to beactuated by hand, it isessential 'that it should be capable of exerting greatpower. This isvrendered 'possible in view of the slight upward movement of the formrequired, usually about one fourth of an inch with each depression ofthe lever., When la number o'f machines are employed ul on a given formthey should'b'eactuated eit er in unison or in successive order, v'thevlatterbeing preferable as requiring but one attendant. In -this way the'form may be elevated as rapidly as itis possible to supplythe materialandi allow it to harden.

It is immaterial how the suspending rod 22, is supported whether fromtop for bottom, 4so long'as itis caused to bear a xed relation to theconcrete structure so thatthe form may always be lifted in -a' verticalplane. .n

'Oneof the @important advantages of the device is that'the lifting forceexerted therebyis always concentric with the axis of .the suspendingrod. Inasmuch as the latter passes through the bore in the web 4, it isalways'maintained Vat the base in 'fixed'relation to the walls oftheform and hence the latter is forced tobe 'continuously moved in avertical plane.

I do 4not 'wish to be limited to the exact construction shown inasmuchas it maybe varied lwithout departing "from the spirit of the invention;nor do I intend "to'be limited to the specific application described, itbeing obvious that it may be utilized for thev lifting of any loadwherein speed of movement 1s not required, provided itis practical tosupply a suspending rod for it to act upon. Having thus described myinvention, I claimw g 1. A device for moving a concrete form in a planeparallel to that of a stationary rod to which said device is adapted tobey inovably connected, comprising, in combination, primary andsecondary frame members, the former of which is in direct operativeconnection with the form to be advanced, an oscillatory head havingopposing` trunnions thereon journaled respectively 1n said primary andsecondary frames, the latter being in the plane of the axis of the rodto which said device is movably connected, a lever fulcrumed upon saidsecond named trunnions, and gripping means upon each of said framesarranged to be in concentric operative relation to said rod foralternately gripping the same against movement in one direction whilefree to slide in the reverse direction n y 2. A device for elevating aconcrete form in a vertical plane by climbing an upright sustaining rod,comprising prlmary and sec-y ondary frame members, the former of whichis in operative connection with the form, an oscillatory head havingcomplementary trunnions thereon, one pairof trunnions being journaled insaid primary frame in the plane of the axis of such sustaining rod andCopies of this patent inay be obtained for thel other in said secondaryframe, a lever fulcrumed upon said'irst named trunnions, and grippingmeans upon each of said frames in concentric relation to said rod forgripping the same against the gravitating action of the load while freeto be alternately released and to slidey upwardly thereon when saidlever is vibrated.

3. A device for elevating a concrete form in a vertical plane byclimbing an upright sustaining rod, comprising primary and secondaryframe members, the former of which is in direct operative connectionwith the form to "be lifted, an oscillatory head having complementarytrunnions thereon journaled krespectively in said primary and secondaryJAMES MACDONALD.

Witnesses:

DAVID I-I. FLETCHER, HARRY I. CROMER.

ve cents each, by addressing the Commissioner of Patents, Washington, D.c.

